This application claims the priority of German application 196 44 586.8 filed in Germany of Oct. 26, 1996, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a fin-coil block for a heat exchanger, especially a charge air cooler that has tubes running parallel to one another and fin-type corrugated ribs through which air flows being located between the tubes, the block being mounted in a rigid frame that consists of two water tanks surrounding the open ends of the tubes and of two side parts connecting these tanks.
Fin-coil blocks of this type are generally manufactured by assembling the tubes and the corrugated ribs to form the desired arrangement in a holder, the tubes are fitted into the tube sheet, and the side parts are added so that the fin-coil block thus formed can be soldered. This type of manufacture is also used for heat exchangers for charge air coolers (German Patent Document DE-OS 23 43 787), in which case however measures are employed to avoid the formation of vapor bubbles in the tubes on the air inlet side, but is relatively expensive.
An object of the present invention is to design a fin-coil block of the species recited at the outset in such form that simpler manufacture is possible.
To achieve this goal, in a fin-tube block of the species recited at the outset, it is proposed that the tubes be made in the form of adjacent channels in plate-shaped extrusion moldings that are stacked on one another, alternating with corrugated ribs and additional extruded sections, in a packet assembly and then assembled to form the fin-tube block.
This design makes it no longer necessary to align the individual tubes with the corrugated ribs. The corrugated ribs and the extruded sections are stacked on top of one another and then soldered as a package using known soldering techniques.
A provision can be made according to preferred embodiments of the invention such that at least two extruded sections are arranged sequentially in the air flow direction and are connected to one another formwise. This measure takes into account that extruded sections cannot be manufactured in all desired widths, so that it becomes necessary to build up a layer of the fin-tube block, composed of extruded sections, from several such extruded sections.
In one advantageous aspect of preferred embodiments of the invention, the extruded sections can be provided with hooks that run parallel to the flow channels and interlock with one another; these hooks advantageously are designed as strips projecting from one side wall to the other, whose grooves are displaced forward to receive the strips of the adjacent extruded section. By virtue of this design, the parts that serve for hooking can also be made integrally with the extruded sections so that when adjacent extruded sections are fitted together, they rest on one another only at their side edges so that the hook strips engage one another.
According to an advantageous feature of the invention, the extruded sections can be made from a metal alloy that can be soldered and in particular can be made of a curable aluminum alloy (AlMgSiO,5). Surprisingly it has been found that extruded sections made from the latter alloy, after their manufacture and after cooling, are subjected to so-called cold curing and increase their strength after a certain period of time.
The extruded sections thus manufactured can be solder-plated, so that they can be soldered in known fashion to the adjoining corrugated ribs to form a fin-tube block.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.